Tension adjustment for vibratory tool

ABSTRACT

For exemplification, the vibratory tool disclosed is a hair clipper with a spring connected with the blade and having an intermediate portion acting as an armature for an alternating current magnet. Near its rear end, the spring curves to extend transversely of the case and abuts an anchorage block. A bolt anchors the spring pivotally yieldably to this block. Accessible from the exterior of the case is a tension adjusting screw having its end in pressure engagement with the free end of the spring to vary the angle of the spring with regard to the block, thereby increasing or decreasing its tension. In one embodiment, all magnetic portions of the vibratory tool are mounted on a primary unit about which is a case of relatively synthetic resin.

' [75] Inventor:

llnite tates atet 1191 TENSION ADJUSTMENT FOR VIBRATORY TOOL Raymond B. Reynolds, Racine, Wis.

[73] Assignee: Andis Clipper Co., Racine, Wis.

[22] Filed: Apr. 26, 1971 [21] Appl. No.: 137,457

[52] US. Cl ..30/2l0, 30/221 [51] Int. Cl ..B26b 19/02, B26b 19/38 [58] Field of Search ..30/43, 43.1, 21,

[56] References Cited UNITED STATES PATENTS 6 1964 Andis ..30/210 x 2,699,509 1/1955 Lee 3,589,007 6/1971 Walton ..30/210 11] gfi fi 14 1 May 29, 1973 Primary ExaminerOthell M. Simpson Assistant Exa minerGary L. Smith Attorney-Wheeler, House & Wheeler [57] ABSTRACT For exemplification, the vibratory tool disclosed is a hair clipper with a spring connected with the blade and having an intermediate portion acting as an armature for an alternating current magnet. Near its rear end, the spring curves to extend transversely of the case and abuts an anchorage block. A bolt anchors the spring pivotally yieldably to this block. Accessible 7 from the exterior of the case is a tension adjusting screw having its end in pressure engagement with the free end of the spring to vary the angle of the spring with regard to the block, thereby increasing or decreasing its tension.

In one embodiment, all magnetic portions of the vibratory tool are mounted on a primary unit about which is a case of relatively synthetic resin.

6 Claims, 4 Drawing Figures l TENSION ADJUSTMENT FOR VIBRATORY TOOL BACKGROUND OF INVENTION It is the object of the invention to produce a spring anchorage and tension adjusting arrangement which is simpler and less expensive than those previously employed.

SUMMARY OF INVENTION The vibratory portion of the spring oscillates with ref erence to the supporting block to which it is pivotally held by a bolt beyond which a free end of the spring projects in spaced relation to the block and is engaged by a pressure bolt threaded through the block and accessible for tension adjustment through an aperture in the case.

In one embodiment herein disclosed, a nut is seated in a recess of the supporting block and the pressure bolt is threaded through it. In another embodiment, the pressure bolt is threaded directly into an angle of the block and seats against an inwardly turned free end of the spring, the bolt being exposed at the side rather than the end of the casing. In this embodiment all of the magnetic parts are optionally mounted on a frame uni tarily positioned in the relatively flexible shell which serves as a casing.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a horizontal view of the base portion of a clipper casing, such portion providing a mounting for all of the mechanical parts herein described.

FIG. 2 is a fragmentary detail view taken in section on the line 2-2 of FIG. 1.

FIG. 3 is a long section of the clipper on the line 3-3 of FIG. 1.

FIG. 4 is a view similar to FIG. 1 showing a modified embodiment of the invention.

DETAILED DESCRIPTION It will be understood that the invention is applicable to any of the many vibratory tools using a spring mounting subject to the flux of an alternating current magnet. The hair clipper illustrated in the drawing is an exemplification of such a tool.

In accordance with generally conventional practice, there is a shear blade 4 attached to the base portion 6 of the clipper case. Upon the shear blade a cutter blade 8 is reciprocable, being held to the shear blade by a spring 10 projecting forwardly and downwardly from the forward extremity of the spring 12. An intermediate portion 14 of the spring serves as an armature for the alternating current magnet 16 mounted at the lower section 6 of the case.

The rear extremity 18 of the spring 12 is turned transversely of the case and is pivotally attached by a bolt 20 to a boss 22 projecting upwardly from the bottom of the case. As will be apparent upon examination of FIG. 1, the laterally projecting extremity 18 of the spring does not seat tightly against the boss but is rockably engaged therewith at 24 and has increasing clearance from the boss toward its free end.

A recess 26 of the boss contains a nut 28 through which is threaded a tension adjusting screw 30. The head 32 of this screw is in alignment with an opening in the case so that the screw can readily be turned by a screwdriver inserted through this opening.

Removal of the top section 38 of the case exposes all of the above described parts. The nut is not fixed to the boss but can readily be inserted or removed. It fits sufficiently snugly in the recess so that the tension adjusting screw can perform its function.

The screw 30 bears against the free end of the spring portion 18 thereby tending to oscillate the spring about its fulcrum at 24 to move its armature portion 141 toward or away from the magnet 16, thus varying tension. The thrust of screw 30 is resisted by the bolt 20, which anchors the spring to the block 22. Retraction of the screw 30 decreases the tension by relieving the free end 18 of the spring of pressure away from the block.

The spring preferably receives support in part from a shoulder 40 of block 22.

The embodiment illustrated in FIG. d has two optionally independent features. The mounting block 220 has a forwardly projecting portion 221 in which the screw 200 is threaded to engage the inwardly turned extremity 180 of the armature spring 120. The bolt 200 which connects the armature spring pivotally to the block 220 functions just as above described to bias the armature toward the magnet while accommodating pivotal yielding adjustment of the armature away from the magnet under thrust of the adjusting bolt 300.

The other optional feature disclosed in FIG. 4 includes the mounting of all magnetic parts, including the magnet 15, the coil I60 and the armature I20 upon a frame 40 which comprises a unitary assembly mounted on frame 42 and enclosed in a housing or case 44 which is preferably made of some relatively soft synthetic resin material which will not crack in the event the clipper falls to the floor. An opening 46 in the case makes the adjusting screw 300 accessible.

It will be understood that the armature spring has a relatively short portion engaged with the block 220 whereby it pivots against the tension of the fulcrum bolt 200 under pressure of the tension adjusting screw 300. The adjustment is essentially the same in the devices of FIGS. 1 and 4.

I claim: ll. In a vibratory magnetic tool having an alternating current electromagnet, a spring armature having a free end connected to a tool, a central portion adjacent said alternating current magnet, and a second end, and a housing comprising a common support for said magnet and said armature,

an anchorage block fixedly secured to the housing, securing means attaching the armature in face engaging relationship to the block near said second end, said securing means acting as a fulcrum, and movable armature adjusting means mounted on said housing and bearing on said second end of the armature in a direction to exert adjustable bias on the armature about said fulcrum in a direction to move the armature away from the magnet.

2. The tool of claim 1 in which said block is provided with a recess, said adjusting means including a nut fitting loosely and non-rotatably in said recess and a screw threaded in said nut and having an end engaging the second end of the armature.

3. The tool of claim 2 in which the block is a part of the housing, the screw being provided with a head engageable by a tool remote from said second end and said housing being provided with an access aperture next to said head.

portion surrounding said frame and block.

6. The tool of claim 1 in which the portion of the armature attached by the securing means extends laterally and the second end extends longitudinally generally parallel to the central portion of the armature acted on by the magnet, said adjusting means comprising a body threadedly engagedin said block having an end bearing on the second end of the armature.

i l t I! 

1. In a vibratory magnetic tool having an alternating current electromagnet, a spring armature having a free end connected to a tool, a central portion adjacent said alternating current magnet, and a second end, and a housing comprising a common support for said magnet and said armature, an anchorage block fixedly secured to the housing, securing means attaching the armature in face engaging relationship to the block near said second end, said securing means acting as a fulcrum, and movable armature adjusting means mounted on said housing and bearing on said second end of the armature in a direction to exert adjustable bias on the armature about said fulcrum in a direction to move the armature away from the magnet.
 2. The tool of claim 1 in which said block is provided with a recess, said adjusting means including a nut fitting loosely and non-rotatably in said recess and a screw threaded in said nut and having an end engaging the second end of the armature.
 3. The tool of claim 2 in which the block is a part of the housing, the screw being provided with a head engageable by a tool remote from said second end and said housing being provided with an access aperture next to said head.
 4. The tool of claim 1 in which the second end of the armature extends laterally respecting the central portion of the armature, the securing means comprising a screw threaded fastener extending through said block and said armature in the laterally extending portion of the armature.
 5. A tool according to claim 1 in which the block, magnet and armature are all mounted unitarily upon a frame, said housing having a relatively yieldable wall portion surrounding said frame and block.
 6. The tool of claim 1 in which the portion of the armature attached by the securing means extends laterally and the second end extends longitudinally generally parallel to the central portion of the armature acted on by the magnet, said adjusting means comprising a body threadedly engaged in said block having an end bearing on the second end of the armature. 